JP2022107814A - Composite cable and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite cable excellent in heat resistance, fogging resistance and terminal workability, and a method for manufacturing the same.

SOLUTION: There are provided a method for manufacturing a composite cable that includes a sheath surrounding the outer surface of a core composed at least of a plurality of large-diameter electric wires having a resin layer on the outer periphery of a conductor and a plurality of small-diameter electric wire having a resin layer on the outer periphery of the conductor which includes a step of molding a silane crosslinkable resin composition containing a base resin, a silane coupling agent graft-coupled to the base resin and a silanol condensation catalyst, on the outer surface of the core, and a step of bringing the molded silane crosslinkable resin composition into contact with water; and a composite cable having a sheath composed of a silanol condensation cured product of the silane crosslinkable resin composition provided on the outer surface of the core.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to composite cables and methods of manufacturing the same.

2. Description of the Related Art In various products such as industrial machines, industrial robots, vehicles (automobiles, trains, etc.), electronic control is adopted to control various operations and functions. For example, in automobiles, there is an anti-lock braking system (ABS) that prevents wheels from locking during sudden braking or braking on a low-friction road to control sliding of the automobile. Further, in recent years, an electric parking brake (EPB), which electrically controls (maintains) a stopped state of a vehicle in place of the conventional hydraulic or mechanical system, has become widespread. These electronic controls typically include control devices, sensors, and cables that electrically connect them. A cable usually consists of an electric wire as a core and a sheath covering the electric wire.
In the various products described above, there is a tendency to use electronic controls extensively, and the number of cables connected to control devices is increasing. When wiring a large number of cables, instead of wiring the cables separately, a composite cable that integrates several cables (a cable in which the core consisting of multiple electric wires that make up the cable is collectively covered with a sheath) is used. Space saving of cable wiring becomes possible by using it (patent document 1).

Japanese Patent No. 5541331

Composite cables are required to have various properties depending on the application. For example, heat resistance is required when the composite cable is exposed (placed) to a high temperature environment. It is also required when using an electric wire with large self-heating as the core. Furthermore, composite cables exposed to high-temperature environments are required not only to have heat resistance but also to have anti-fogging properties (characteristics that prevent fogging or contamination of the vicinity of the composite cable installation portion). For example, if a composite cable used in a lighting system or interior does not exhibit sufficient fogging resistance, it will fog up glass covers, car windows, etc. when exposed to high temperatures. Also, if a composite cable that does not exhibit sufficient fogging resistance is installed in the above ABS or EPB, the control device and sensors will become cloudy and dirty.

In addition, the diameter of the electric wire that constitutes the core of the composite cable is appropriately selected according to the application, and wires with different diameters are usually used. Therefore, it is difficult to peel off the sheath of the end portion of the composite cable during installation (the end workability is poor). Peeling the sheath is particularly difficult if no separator is interposed between the sheath and the core.

An object of the present invention is to provide a composite cable excellent in heat resistance, fogging resistance and terminal workability, and a method for manufacturing the same.

The present inventors created a composite cable having a high level of heat resistance, fogging resistance, and terminal processability by forming the sheath of a composite cable by a silane crosslinking method using a specific silane-crosslinkable resin composition. I found what I could do. Based on this knowledge, the present inventors have made further studies and completed the present invention.

That is, the above problems of the present invention are solved by the following means.
<1> A composite cable having a sheath surrounding the outer surface of a core composed of at least a plurality of large-diameter wires having a resin layer on the outer periphery of the conductor and a plurality of small-diameter wires having a resin layer on the outer periphery of the conductor. A manufacturing method comprising:
molding a silane crosslinkable resin composition containing a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst on the outer surface of the core;
contacting the molded silane crosslinkable resin composition with water;
A method of manufacturing a composite cable having
<2> The method for producing a composite cable according to <1>, wherein the base resin contains at least one of ethylene rubber and styrene elastomer.
<3> Manufacture of the composite cable according to <1> or <2>, wherein the silane crosslinkable resin composition contains 1 to 15 parts by mass of the silane coupling agent with respect to 100 parts by mass of the base resin. Method.
<4> The method for producing a composite cable according to any one of <1> to <3>, wherein the base resin contains an organic mineral oil.
<5> The composite cable according to any one of <1> to <4>, wherein the silane crosslinkable resin composition contains 10 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the base resin. Production method.
<6> A composite cable having a sheath surrounding the outer surface of a core composed of at least a plurality of large-diameter wires having a resin layer on the outer periphery of the conductor and a plurality of small-diameter wires having a resin layer on the outer periphery of the conductor. There is
A composite cable in which the sheath is made of a silanol condensation cured product of the silane crosslinkable resin composition described below.
<Silane crosslinkable resin composition>
A silane crosslinkable resin composition containing a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst <7> The base resin comprises at least one of ethylene rubber and styrene elastomer. The composite cable according to <6>.
<8> The composite cable according to <6> or <7>, wherein the silane crosslinkable resin composition contains 1 to 15 parts by mass of the silane coupling agent with respect to 100 parts by mass of the base resin.
<9> The composite cable according to any one of <6> to <8>, wherein the base resin contains an organic mineral oil.
<10> The composite according to any one of <6> to <9>, wherein the silane crosslinkable resin composition contains 10 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the base resin. cable.
<11> The composite cable according to any one of <6> to <10>, which is used for vehicle brake control.
<12> Two of the plurality of large-diameter wires serve as a pair of power wires that supply power from the control device of the electric parking brake to the actuator,
Two of the plurality of thin wires are used as a pair of signal wires for transmitting signals from the antilock braking system sensor to the antilock braking system control device.
The composite cable according to <11>.

In the present invention, a numerical range represented by "to" means a range including the numerical values before and after "to" as lower and upper limits.
In addition, the expression "consisting at least of XXX" includes not only the embodiment formed of XXX, but also the embodiment formed of XXX and other materials, components, and the like.

The composite cable of the present invention is excellent in heat resistance, fogging resistance and terminal workability. Also, the method for manufacturing a composite cable of the present invention can manufacture a composite cable having the above-described excellent properties.

FIG. 1 is an end perspective perspective view schematically showing a preferred embodiment of the composite cable of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the outline of the apparatus used for the bending endurance test in an Example.

[Composite cable]
The composite cable of the present invention includes a sheath surrounding the outer surface of a core composed of at least a plurality of large-diameter wires having a resin layer on the outer periphery of the conductor and a plurality of small-diameter wires having a resin layer on the outer periphery of the conductor. ing. This sheath is formed of a silanol condensation cured product of a silane crosslinkable resin composition, which will be described later.
The composite cable of the present invention can be preferably manufactured by the manufacturing method of the composite cable of the present invention, which will be described later, and has high levels of heat resistance, fogging resistance, and terminal workability. Since the composite cable of the present invention exhibits high fogging resistance, it can be called a fogging-resistant composite cable.

The details of why the composite cable of the present invention has a high level of heat resistance, fogging resistance and terminal workability are not yet clear, but are considered as follows.
In the composite cable of the present invention, the sheath is formed by a silane cross-linking method using a silane cross-linkable resin composition (silanol condensation cured product of the silane cross-linkable resin composition). Therefore, in addition to improving heat resistance by cross-linking, silanol condensation cured products can be obtained without generating low molecular weight components (volatile substances) such as decomposition products and by-products that cause fogging in the series of chemical reactions of the silane cross-linking method. The amount of low molecular weight components mixed in is small. In addition, this cured product is easy to peel, and does not excessively heat the insulated wire and the silane crosslinkable resin composition when forming the sheath in the silane cross-linking method, and even in a mode in which a separator is not interposed, the insulated wire can be cured. Firm adhesion between the resin layer and the sheath can be prevented. Furthermore, even during molding, the heating that impairs the peelability is only for a short period of time inside the head, and the adhesion can be minimized. On the other hand, in the chemical cross-linking method, the sheath is exposed to high temperature and high pressure for a long period of time.

In the present invention, that the sheath surrounds the outer surface of the core means that the sheath is arranged (covered) on the outer surface of the core, that is, the sheath encloses the core as a whole. In the present invention, the sheath collectively covers (incorporates) the core with a layer called a separator (a layer made of paper, cloth, or a resin such as polyethylene terephthalate) interposed to improve terminal workability. However, since the composite cable of the present invention is excellent in terminal workability as described above, it is preferable that the cores are collectively and directly covered.
The composite cable of the present invention is not particularly limited except for the material forming the sheath, and the same configuration as known composite cables in which two or more sets of electric wires are integrated can be applied.
A preferred form of the composite cable of the present invention is, like the composite cable 1 shown in FIG. It has a core consisting of at least a set (a pair) of small-diameter electric wires 3 having a resin layer 32 on the outer periphery, and a sheath 4 surrounding the outer surface of the core. A core (also referred to as a conductor core) composed of at least two large-diameter wires 2 and two small-diameter wires 3 is composed of three wires, ie, the twisted wires of the small-diameter wires 3 and the two large-diameter wires 2. It is configured as a stranded wire that is twisted together.
A composite cable of the present invention and embodiments thereof will be described below.

<Core>
The composite cable of the present invention includes at least two types of wires having different diameters, specifically, a plurality of large-diameter wires and a plurality of small-diameter wires, as cores. The large-diameter wire is the wire with the largest diameter among the wires forming the conductor core, and the thin-diameter wire is the wire with the smallest diameter among the wires forming the conductor core.
A large-diameter electric wire and a small-diameter electric wire are used for different purposes. A large-diameter wire and a small-diameter wire are usually used as a pair, but three or more wires can also be used as a set. When the large-diameter electric wire and the small-diameter electric wire each constitute a plurality of sets, each set may be used for the same purpose or for different purposes.
The arrangement state of the large-diameter electric wire and the small-diameter electric wire in the conductor core is not particularly limited, and an arrangement state applied to a normal core can be appropriately adopted. For example, they may be arranged independently of each other in parallel (side by side), or they may be arranged in a twisted manner (twisted wire). From the viewpoint of flexibility (softness) and resistance to bending as a composite cable, it is preferable to arrange them by twisting them together. The large-diameter electric wire and the small-diameter electric wire may each constitute a stranded wire, but preferably constitute one stranded wire as a whole. In this case, the large-diameter wire and the small-diameter wire may be stranded wires, respectively, but as shown in FIG. It is preferable to use a twisted wire with a uniform thickness. The number of wires, the arrangement of wires, the direction of twisting, the pitch of twisting, and the like when twisting the wires are not particularly limited, and are appropriately set according to the application. When the electric wires are twisted together, it is also possible to interpose a resin such as polyethylene terephthalate (PET) or polypropylene (PP) between them. This makes it possible to freely control the shape of the conductor core.

(thick wire)
The large-diameter electric wire only needs to have a resin layer on the outer periphery of the conductor, and a normal (insulated) electric wire can be used without particular limitations.
The composite cable of the present invention may have at least two large-diameter wires, preferably 2 to 6 wires, and more preferably 2 to 4 wires. Also, the plurality of large-diameter wires may be incorporated as one set, or may be divided into a plurality of sets and incorporated.
The outer diameter of the large-diameter wire is not particularly limited as long as it is thicker than the small-diameter wire, which will be described later, and can be appropriately determined according to the application. Since the composite cable of the present invention exhibits high heat resistance, an insulated wire with high self-heating can be used. Specifically, the outer diameter and conductor cross-sectional area can be within the following ranges. For example, it is preferably 1.0 to 5.0 mm, more preferably 2.0 to 4.0 mm, in terms of strength and flexibility. The conductor cross-sectional area of the large-diameter electric wire is appropriately determined depending on the application, but is preferably 0.3 to 8.0 SQ, more preferably 0.5 to 3.0 SQ.
A large-diameter electric wire is used for applications in which a larger current flows than a small-diameter electric wire described later.

- Conductor -
The conductor is not particularly limited, and may be a strand or a twisted wire obtained by twisting a plurality of strands, preferably a twisted wire. The cross-sectional shape of the conductor (strand wire) is not particularly limited, and may be circular in cross section (round wire) or rectangular in cross section (rectangular wire). The material forming the conductor (strand wire) is not particularly limited, and examples thereof include copper, aluminum, and alloys thereof.
The number of strands constituting the twisted wire is not particularly limited as long as it is plural (two or more). The arrangement of the strands, the twisting direction, the twisting pitch, etc., when twisting the strands are appropriately set according to the application.
Although the outer diameter of the conductor is not particularly limited, it is preferably larger than the conductor of the small-diameter electric wire described later, and can be appropriately determined according to the application. For example, from the viewpoint of strength and flexibility, the outer diameter is preferably 0.5 to 4.0 mm, more preferably 1.0 to 3.5 mm. The outer diameter of the wires constituting the stranded wire is not particularly limited as long as it satisfies the outer diameter of the conductor, but is preferably 0.05 to 0.5 mm, more preferably 0.05 to 0.3 mm.

- Resin layer -
The resin layer may be a single layer or multiple layers as long as it surrounds the outer peripheral surface of the conductor (covers the conductor). The resin layer is usually made of heat-resistant resin. The heat-resistant resin is not particularly limited, and any resin that forms a normal (insulated) electric wire can be used without any particular limitation. Examples include thermoplastic resins and thermosetting resins, and more specifically, (crosslinked) polyethylene, polyamide, polyamideimide (PAI), polyimide (PI), polyurethane, chloroprene rubber, ethylene-vinyl acetate copolymer. rubber (EVA rubber) made of. The resin layer may contain various commonly used additives.
The (total) layer thickness of the resin layer is not particularly limited, and can be appropriately determined according to the application and the like. For example, it is preferably 0.2 to 1.5 mm, more preferably 0.2 to 1.0 mm, in terms of heat resistance, flexibility and abrasion resistance.
In the present invention, when the conductor is a stranded wire, the layer thickness of the resin layer is the shortest distance between the virtual circumscribed circle of all the strands of the conductor and the outer contour of the resin layer in a cross section perpendicular to the axis of the electric wire. means

(thin wire)
The small-diameter electric wire only needs to have a resin layer on the outer periphery of the conductor, and ordinary (insulated) electric wires can be used without particular limitations.
The composite cable of the present invention may have at least two fine wires, preferably 2 to 12 wires, and more preferably 2 to 6 wires. Also, the plurality of small-diameter wires may be incorporated as one set, or may be divided into a plurality of sets and incorporated.
The small-diameter electric wire is an electric wire having an outer diameter smaller than that of the large-diameter electric wire, and has the same configuration, material, etc. as the large-diameter electric wire.
The outer diameter of the small-diameter electric wire can be appropriately determined according to the application and the like. more preferred. The difference in outer diameter from the large-diameter wire is not particularly limited, but is preferably 0.5 to 2.0 mm, for example. The conductor cross-sectional area of the small-diameter electric wire is appropriately determined according to the application and the like, but is preferably 0.05 to 2.0 SQ, more preferably 0.05 to 1.25 SQ. The outer diameter of the conductor in the small-diameter wire is appropriately determined depending on the application, and is preferably 0.3 to 2.0 mm, more preferably 0.3 to 1.5 mm. When the conductor is a stranded wire, the outer diameter of the wire constituting the stranded wire is not particularly limited as long as it satisfies the outer diameter of the conductor. 0.3 mm is more preferred. The (total) layer thickness of the resin layer is not particularly limited, and can be appropriately determined according to the application and the like. For example, it is preferably 0.2 to 1.0 mm, more preferably 0.2 to 0.5 mm, in terms of heat resistance, flexibility and abrasion resistance.

It is preferable to use a crosslinked polyethylene electric wire as the large-diameter electric wire and the small-diameter electric wire. Such wires include, for example, cross-linked polyethylene insulated heat-resistant low-voltage wires for automobiles (AEX) and ultra-thin cross-linked polyethylene insulated heat-resistant low-voltage wires for automobiles (AESSX ), which has a heat resistance temperature equivalent to 120° C. and uses cross-linked polyethylene as a base resin. The crosslinked polyethylene electric wire may be produced appropriately, or a commercially available one may be used.

(Other electric wires)
The conductor core may have an (insulated) wire in addition to the large-diameter wire and the small-diameter wire. This electric wire may have an outer diameter thinner than that of the large-diameter electric wire and thicker than that of the small-diameter electric wire.

<sheath>
The composite cable of the present invention has a sheath covering the outer surface of the conductor core. This sheath can be a sheath for a normal composite cable, except that it is formed of a silanol condensation cured product of a silane crosslinkable resin composition, which will be described later.
The sheath may be a single layer or multiple layers, and the layer thickness can be appropriately determined depending on the application. The layer thickness of the sheath is preferably from 0.5 to 3.0 mm, preferably from 0.8 to 2.0 mm is more preferred. In the present invention, the layer thickness of the sheath means the shortest distance between the virtual circumscribed circle of all the conductors forming the conductor core and the outer contour line of the sheath in a cross section perpendicular to the axis of the composite cable.
The cross-sectional shape (outer contour) of the composite cable is not particularly limited, but is usually circular.
The outer diameter of the sheath (which is synonymous with the diameter of the composite cable and corresponds to the diameter of the outer contour line) can be appropriately determined depending on the application, and is not particularly limited. For example, it is preferably 5.0 to 30.0 mm, more preferably 5.0 to 15.0 mm, in terms of heat resistance, terminal workability and fogging resistance, as well as flexibility, bending resistance and abrasion resistance. .

The sheath consists of a silanol condensation cured product of the silane crosslinkable resin composition. As a result, as described above, the composite cable can be endowed with high levels of heat resistance, fogging resistance, and terminal workability.
When a sheath is formed from a cured product of a silane crosslinkable resin composition containing at least one of ethylene rubber and styrene elastomer as a base resin, in addition to heat resistance, fogging resistance and terminal processability, bending resistance and further A composite cable having excellent flexibility can be obtained. Such a composite cable can be easily bent (with a weak force), and the efficiency of wiring processing (assembly processing) can be improved. In addition, when the sheath is formed from a cured product of a silane crosslinkable resin composition containing an inorganic filler in a content described later, high abrasion resistance can be imparted to the composite cable.
The details of the silane crosslinkable resin composition and its silanol condensate cured product will be described later in the manufacturing method of the composite cable.

[Uses of composite cables]
INDUSTRIAL APPLICABILITY The composite cable of the present invention is suitably used as an electronic control cable for various products, such as industrial machines, industrial robots, and vehicles. Above all, it is excellent in heat resistance and anti-fogging properties, so it is more preferably used as a composite cable exposed to (arranged) in a high-temperature environment or as a composite cable requiring fogging properties. In particular, it is suitably used for automobile brake control (ABS and EPB), lighting equipment, interior decoration, robot control, and the like.
Moreover, a preferred composite cable exhibiting high bending resistance is more preferably used as an electronic control cable for a product having two or more members that move relative to each other. For example, the cables used in the ABS and EPB brake control devices described above are usually exposed to vibrations due to running and changes in the positions of tires and the like with respect to the vehicle body. However, the composite cable of the present invention exhibits sufficient resistance to vibrations, positional fluctuations, and the like in brake control devices and the like. Therefore, the composite cable of the present invention, particularly a preferred composite cable exhibiting high bending resistance, is suitably used for the above-mentioned brake control (ABS and EPB) of automobiles, movable parts of industrial robots, and the like.

When used in an automobile brake system, it is preferable that a pair of two large-diameter wires of the composite cable be used as a power wire for EPB, and a pair of two small-diameter wires be used as a signal wire for ABS. A large-diameter wire (power wire) is electrically connected to a control device for an electric parking brake mounted on the vehicle body and to an actuator provided on the tire side, and supplies power from the control device to the actuator. On the other hand, the small diameter electric wire (signal wire) is electrically connected to the ABS control device mounted on the vehicle body and the ABS sensor arranged on the tire side, and from the ABS sensor to the ABS control device (locked state of the tire). ) to transmit a signal. Furthermore, the cable that transmits the signal for controlling the brake caliper based on this signal may be the same as or different from the thin wire (signal wire), and is determined as appropriate.

Composite cables are typically fabricated from small and large wire ends (terminals) and connected to predetermined control devices and sensors. At this time, the sheath of the terminal of the composite cable of the present invention can be removed (peeled) as desired (excellent terminal workability). For example, it is possible to prevent a portion of the sheath from remaining on the conductor core without being peeled off, or to prevent the occurrence of whiskers extending from the cut end face of the sheath, thereby making it possible to easily remove a predetermined sheath. Here, the whiskers are linear bodies (hairy bodies) derived from the sheath that remain on the cut end face of the sheath (extend from the cut end face) because the sheath cannot be cut to the surface of the conductor core in the thickness direction. Say.
Since the preferred composite cable of the present invention is excellent in bending resistance and flexibility, it is possible to easily bend the terminal-processed composite cable for wiring work.

[Manufacturing method of composite cable]
The materials or components used to manufacture the composite cable of the present invention will now be described.
<Electric wire>
In manufacturing the composite cable of the present invention, two or more types of wires having different diameters, for example, the crosslinked polyethylene wires as the large-diameter wire and the small-diameter wire, are prepared. This electric wire may be appropriately manufactured according to a normal method, or a commercially available product may be used.

<Silane crosslinkable resin composition>
The silane crosslinkable resin composition used to form the sheath contains a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst.

(base resin)
The base resin is a resin having a graft reaction site of a silane coupling agent and a site capable of graft reaction in the silane cross-linking (in the presence of radicals generated from the organic peroxide described later) in the main chain or at the end thereof. is not particularly limited. Examples of the sites that can be crosslinked or sites that can be grafted include unsaturated bond sites of carbon chains, carbon atoms having hydrogen atoms, and the like.
Examples of the base resin include various resins commonly used for silane cross-linking, such as polyolefin resins, ethylene rubbers, and styrene elastomers. The base resin preferably contains at least one of ethylene rubber and styrene elastomer.
The base resin may contain organic mineral oil.

- Ethylene rubber -
The ethylene rubber is not particularly limited as long as it is a rubber (including an elastomer) composed of a copolymer obtained by copolymerizing a compound having an ethylenically unsaturated bond, and known rubbers can be used. The ethylene rubber preferably includes a bipolymer rubber of ethylene and an α-olefin, a terpolymer rubber of ethylene, an α-olefin and a diene, and the like. The diene component of the terpolymer may be a conjugated diene component or a non-conjugated diene component, although the non-conjugated diene component is preferred.
As the α-olefin constituent, each α-olefin constituent having 3 to 12 carbon atoms is preferred. Conjugated diene constituents include, for example, constituents such as butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene, with butadiene constituents being preferred. Specific examples of non-conjugated diene constituents include constituents such as dicyclopentadiene (DCPD), ethylidene norbornene (ENB), and 1,4-hexadiene.
Ethylene-propylene rubber (EPM) is preferred as the bi-copolymer rubber, and ethylene-propylene-diene rubber (EPDM) is preferred as the terpolymer rubber.
Ethylene rubber may be used alone or in combination of two or more.

- Styrene Elastomer -
The styrene-based elastomer refers to a polymer composed of an aromatic vinyl compound in its molecule. Examples of such styrene-based elastomers include block copolymers and random copolymers of conjugated diene compounds and aromatic vinyl compounds, or hydrogenated products thereof. Examples of such styrene elastomers include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), hydrogenated SIS, styrene-butadiene-styrene block copolymer. polymer (SBS), hydrogenated SBS, styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butadiene rubber (SBR), Examples include hydrogenated styrene-butadiene rubber (HSBR).
Styrenic elastomers may be used alone or in combination of two or more.

- Polyolefin resin -
The polyolefin resin is not particularly limited as long as it is a resin composed of a homopolymer or copolymer of a compound having an ethylenically unsaturated bond, and those used for ordinary electric wires or cables can be used. Examples thereof include resins such as polyethylene, polypropylene, ethylene-α-olefin copolymers, polyolefin copolymers having an acid copolymerization component or an acid ester copolymerization component, and rubbers or elastomers of these polymers. The rubber or elastomer may be anything other than ethylene rubber and styrene elastomer, and examples thereof include copolymer rubber of alkyl acrylate and ethylene (ethylene acrylic rubber). Among them, resins such as polyethylene, polypropylene, ethylene-α-olefin copolymers, and polyolefin copolymers having an acid copolymer component are preferred. Polyethylene resin is more preferable because it has a large effect of improving flex resistance and abrasion resistance when used in combination with ethylene rubber or styrene elastomer.
The polyethylene resin may be a polymer resin containing an ethylene component, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), ultra-high molecular weight polyethylene (UHMW-PE), linear low-density polyethylene. (LLDPE), very low density polyethylene (VLDPE). Among them, linear low-density polyethylene and low-density polyethylene are preferable.
Polyolefin copolymer resins having an acid copolymer component or an acid ester copolymer component include, for example, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-alkyl(meth)acrylate. Each resin made of a copolymer (preferably having 1 to 12 carbon atoms) is exemplified.
One type of polyolefin resin may be used alone, or two or more types may be used in combination.

- Organic mineral oil -
As the organic mineral oil, those commonly used in resin compositions can be used without particular limitation, and include paraffinic oils and naphthenic oils, with paraffinic oils being preferred. One type of organic mineral oil may be used alone, or two or more types may be used in combination.

- Content of each component in base resin -
The content of each component in the base resin is not particularly limited, and is appropriately determined according to the application and properties.
For example, when the base resin contains ethylene rubber and a styrene elastomer, the total content of these in the base resin is preferably 10% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The upper limit of the total content is preferably 50% by mass or less, more preferably 45% by mass or less.
The content of ethylene rubber or styrene-based elastomer in the base resin may be appropriately set within a range that satisfies the above total content. For example, the content of ethylene rubber or styrene-based elastomer is 5 to 25% by mass is preferable, and 10 to 20% by mass is more preferable.

When the base resin contains a polyolefin resin, the total content of these in the base resin is not particularly limited, but is preferably 10 to 50% by mass, more preferably 20 to 40% by mass. In the present invention, the content of each resin included in the polyolefin resin in the base resin is appropriately set within a range that satisfies the above content of the polyolefin resin. For example, the polyethylene resin content is preferably 0 to 50% by mass, more preferably 20 to 30% by mass.
When the base resin contains an organic mineral oil, the content of the organic mineral oil in the base resin is not particularly limited, but is preferably 0 to 40% by mass, more preferably 10 to 35% by mass.
In the base resin, the ratio (C _E :C _O ) of the (total) content of ethylene rubber and styrene elastomer (C _E ) to the content of organic mineral oil (C _O ) is 50:50 to 75:25. is preferred, and 55:45 to 65:35 is more preferred.

The resin composition may contain other resins than the base resin and various additives such as antioxidants. Other resins and additives may be used alone or in combination of two or more.

(Silane coupling agent grafted to base resin)
The silane coupling agent undergoes a grafting reaction with the base resin in the silane crosslinkable resin composition.
Such a silane coupling agent is preferably obtained by grafting to the base resin in the presence of an organic peroxide. Details of the grafting reaction will be described later.
The silane coupling agent and the organic peroxide used in the grafting reaction may be of one type or two or more types.

- Silane coupling agent -
As the silane coupling agent used for the grafting reaction, a grafting reaction site (group or atom) and a hydrolyzable silyl group capable of silanol condensation is not particularly limited. Examples of such a silane coupling agent include silane coupling agents used in ordinary silane cross-linking methods. Examples of such silane coupling agents include silane coupling agents having a vinyl group or a (meth)acryloyl group as a graft reaction site. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinyldimethoxyethoxysilane, vinyldimethoxybutoxysilane, vinyldiethoxybutoxysilane, allyltrimethoxysilane, allyltriethoxysilane, vinyltriacetoxysilane. vinylsilane such as methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, and (meth)acryloxysilane such as methacryloxypropylmethyldimethoxysilane. Among them, vinyltrimethoxysilane or vinyltriethoxysilane is particularly preferred.

- Organic peroxide -
The organic peroxide used for the grafting reaction generates radicals at least by thermal decomposition, and serves as a catalyst for the grafting reaction by radical reaction of the silane coupling agent to the base resin (grafting reaction site of the silane coupling agent and It is a covalent bond-forming reaction with a graftable site of the base resin, which is also called a (radical) addition reaction.). As such an organic peroxide, those having the above functions and used for radical polymerization or a normal silane cross-linking method can be used without particular limitation. For example, benzoyl peroxide, dicumyl peroxide (DCP), 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane or 2,5-dimethyl-2,5-di-(tert- Butylperoxy)hexyne-3 is preferred.
The decomposition temperature of the organic peroxide is preferably 80 to 195°C, particularly preferably 125 to 180°C. The decomposition temperature is the temperature at which heat absorption or heat generation starts when heated from room temperature at a heating rate of 5° C./min in a nitrogen gas atmosphere by thermal analysis such as DSC method.

- Base resin grafted with silane coupling agent -
In the silane crosslinkable resin composition, as the base resin and the silane coupling agent grafted to the base resin, an appropriately synthesized or commercially available base resin to which a silane coupling agent is grafted (silane graft resin ) can be used.

(Silanol condensation catalyst)
The silanol condensation catalyst causes (promotes) the silanol condensation reaction of the silane coupling agent grafted to the base resin in the presence of water.
Such silanol condensation catalysts are not particularly limited, and examples thereof include organotin compounds, metallic soaps, platinum compounds and the like. Examples of organic tin compounds include organic tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctiate, and dibutyltin diacetate.

- Carrier resin -
The silanol condensation catalyst is preferably used as a mixture (catalyst masterbatch) with a resin (carrier resin). Although the resin is not particularly limited, any of the resins described above for the base resin can be used.

(Inorganic filler)
The silane crosslinkable resin composition may contain one or more inorganic fillers.
The inorganic filler is not particularly limited, but in terms of heat resistance and wear resistance, the surface thereof has a site that can form a hydrogen bond with a hydrolyzable silyl group of a silane coupling agent or a chemical bond by a covalent bond. It is preferable to have a site that can be used. The sites that can be chemically bonded to the hydrolyzable silyl groups of the silane coupling agent include OH groups (hydroxyl groups, water molecules of water containing water or water of crystallization, OH groups such as carboxyl groups), amino groups, SH groups, and the like.
Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whiskers, and hydrated aluminum silicate. , hydrated magnesium silicate, basic magnesium carbonate, metal hydrates such as compounds having hydroxyl groups or water of crystallization such as hydrotalcite, boron nitride, silica (crystalline silica, amorphous silica, etc. ), carbon, clay, zinc oxide, tin oxide, titanium oxide, molybdenum oxide, antimony trioxide, silicone compounds, quartz, talc, zinc borate, white carbon, zinc borate, zinc hydroxystannate, and zinc stannate. Among them, at least one selected from the group consisting of silica, aluminum hydroxide, magnesium hydroxide, calcium carbonate and antimony trioxide is preferable.
The inorganic filler is preferably particles, and the average particle size thereof is appropriately set.
The inorganic filler may be surface-treated with an ordinary surface-treating agent.

- Content of each component in the silane crosslinkable resin composition -
The content of the base resin in the silane crosslinkable resin composition is not particularly limited, but is preferably 30 to 80% by mass, more preferably 40 to 70% by mass.
The content of each component other than the base resin is set with respect to 100 parts by mass of the base resin. 100 parts by mass of the base resin means the total content of each component constituting the base resin, and usually the total amount of the resin component (e.g., ethylene rubber, styrene elastomer and polyolefin resin) and organic mineral oil. means.
In the silane crosslinkable resin composition, the content of each component constituting the base resin in the base resin is as described above.
The content of the silane coupling agent in the silane crosslinkable resin composition is preferably 1 to 15 parts by mass, more preferably 3 to 12 parts by mass, and 4 to 12 parts by mass with respect to 100 parts by mass of the base resin. More preferred. The content of the silane coupling agent is the content converted to the content of the silane coupling agent before the grafting reaction.
The content of the silanol condensation catalyst in the silane crosslinkable resin composition is not particularly limited, but is preferably 0.001 to 0.6 parts by mass, more preferably 0.01 to 0.01 parts by mass, relative to 100 parts by mass of the base resin. It is 0.4 parts by mass.
When the silane crosslinkable resin composition contains an inorganic filler, the content of the inorganic filler is preferably 10 to 150 parts by mass, more preferably 30 to 120 parts by mass, more preferably 50 to 100 parts by mass, based on 100 parts by mass of the base resin. Parts by mass are more preferred.

The amount of other resins and additives that can be used in addition to the above components is appropriately set within a range that does not impair the object of the present invention.

A method of manufacturing a composite cable of the present invention (manufacturing method of the present invention) will be described.
The production method of the present invention comprises the steps of placing (molding) a silane crosslinkable resin composition on the outer surface of a conductor core, and then contacting this silane crosslinkable resin composition with water.
A conductor core and a silane crosslinkable resin composition are prepared when carrying out the manufacturing method of the present invention. A preferred embodiment of the production method of the present invention, which includes preparation of the silane crosslinkable resin composition, has the following steps (1) to (3).
Step (1): The base resin, the silane coupling agent, the silanol condensation catalyst, and preferably an inorganic filler are melt-mixed in the presence of an organic peroxide at a temperature equal to or higher than the decomposition temperature of the organic peroxide. Step (2): Place the silane crosslinkable resin composition on the outer peripheral surface of the conductor core Step (3): Crosslink the silane crosslinkable resin composition by contacting it with water

<Production of conductor core>
When the conductor core has a stranded wire structure, prepared electric wires are used to form a stranded wire by twisting them together by a normal method. For example, the manufacturing method in the example can be mentioned.

<Preparation of silane crosslinkable resin composition>
The silane crosslinkable resin composition contains a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst.
This silane crosslinkable resin composition can be prepared by mixing each component using a commercially available silane graft resin. The mixing method is not particularly limited as long as it is a method commonly used for preparing compositions, and various mixing apparatuses can be used. The mixing conditions are also not particularly limited and are appropriately set, but usually the mixing is performed while the base resin is molten.
The content (blending amount) of each component in the silane crosslinkable resin composition is as described above.

The above preparation is preferably carried out by the following step (1).
Step (1): The base resin, the silane coupling agent, the silanol condensation catalyst, and preferably an inorganic filler are melt-mixed in the presence of an organic peroxide at a temperature equal to or higher than the decomposition temperature of the organic peroxide. process

In step (1), the mixing order of each component is not particularly limited, and the components may be mixed in any order. As the melt-mixing conditions, the conditions in step (1-1b) described later can be applied.
In this step, the base resin and the silane coupling agent are grafted by radicals generated from the organic peroxide. Thereby, a silane graft resin is synthesized, and a silane crosslinkable resin composition containing this silane graft resin is prepared as a reaction composition. The synthesized silane graft resin is also called silane crosslinkable resin. This silane-crosslinkable resin composition contains a silane-grafted resin obtained by grafting a silane coupling agent to a base resin to an extent that it can be molded by the step (2) described below.

In step (1), each component can be melt-mixed (also referred to as melt-kneading or kneading) at once, but the above-mentioned components are melted by the following steps (1-1) and (1-2). Mixing is preferred.

Step (1-1): A step of melt-mixing the base resin, the silane coupling agent, and preferably an inorganic filler in the presence of an organic peroxide at a temperature equal to or higher than the decomposition temperature of the organic peroxide. (1-2): A step of melt mixing a silane masterbatch and a silanol condensation catalyst to prepare a silane crosslinkable resin composition.

The base resin and the silane coupling agent are subjected to a grafting reaction by melt-mixing in step (1-1). Thereby, a silane masterbatch (silane MB) containing a silane graft resin is prepared. The silane MB contains a silane-grafted resin obtained by grafting a silane coupling agent to a base resin to the extent that it can be molded by the step (2) described below.

In the step (1-1), the mixing order of the respective components is not particularly limited and may be mixed in any order, and the above respective components may be melt-mixed at once. In this case, it is preferable to dry-blend the above components in advance and then melt-mix them. As the method and conditions for dry blending and melt mixing, the methods and conditions described in the following steps (1-1a) and (1-1b) can be adopted.

In the method for preparing the silane crosslinkable resin composition, the step (1-2) of melt-mixing the silane MB and the silanol condensation catalyst is then carried out.
In step (1-2), when part of the base resin is melt-mixed in step (1-1) or step (1-1b), a mixture (catalyst masterbatch) with a carrier resin is used as a silanol condensation catalyst. can be used. A catalyst masterbatch (catalyst MB) can be prepared, for example, by melt mixing the remainder of the base resin and a silanol condensation catalyst. The melt-mixing at this time may be any method as long as it is performed while the carrier resin is melted, and can be performed, for example, in the same manner as the melt-mixing in the above step (1-1b). The mixing temperature can be set to, for example, 80-250°C, more preferably 100-240°C.
The silane MB and the silanol condensation catalyst or catalyst MB can be mixed by any method as long as the method is carried out while the base resin is molten, and can be carried out, for example, in the same manner as the melt mixing in step (1-1b). The mixing temperature can be set to, for example, 80-250°C, more preferably 100-240°C.
The blending amount of the silanol condensation catalyst is as described above.
In this step, resins other than the base resin, inorganic fillers, and the like can also be mixed.

Thus, a silane crosslinkable resin composition is obtained as a molten mixture of the silane MB and the silanol condensation catalyst or catalyst MB. This silane crosslinkable resin composition is an uncrosslinked body in which the hydrolyzable silyl groups derived from the silane coupling agent are not silanol-condensed. Practically, partial cross-linking (partial cross-linking) is unavoidable due to melt-mixing in step (1-2), but it is preferable that moldability in step (2) described below is maintained.

In the method for preparing a silane crosslinkable resin composition, when an inorganic filler is used, it is preferable to mix each component in two steps of the following steps (1-1a) and (1-1b) as step (1-1). .
Step (1-1a): Step of pre-mixing an inorganic filler and a silane coupling agent to prepare a mixture Step (1-1b): The mixture obtained in Step (1-1a) and a base resin are combined with an organic Melting and mixing in the presence of a peroxide at a temperature above the decomposition temperature of the organic peroxide

In the above step (1-1) or step (1-1b), all of the base resin can be melt-mixed. It is preferable to melt and mix as In this case, 100 parts by mass of the base resin means the total amount of the base resin blended in step (1-1) or step (1-1b) and the base resin blended in step (1-2). . A portion of the base resin to be blended is preferably 50 to 98% by mass, and the remainder is preferably 2 to 50% by mass.

In step (1-1a), the method for pre-mixing the inorganic filler and the silane coupling agent is not particularly limited, and wet mixing or dry mixing may be used. In the present invention, dry mixing (dry blending) in which the silane coupling agent is added to the inorganic filler with or without heating and mixed is preferred. The mixing temperature is preferably 10 to 60° C., more preferably around room temperature (25° C.) (for example, 20 to 35° C.), and can be set for several minutes to several hours.
As a result of this mixing, an inorganic filler with a silane coupling agent bonded or adsorbed with a strong bond (via a hydrolyzable silyl group that can be silanol-condensed) on the surface (site that can be chemically bonded) and a silane coupling agent with a weak bond on the surface. An inorganic filler to which a ring agent is bound or adsorbed can be prepared. Weak bonds include interactions due to hydrogen bonds, interactions between ions, partial charges or dipoles, actions due to adsorption, etc. Strong bonds include chemical bonds with sites that can be chemically bonded on the surface of the inorganic filler. etc. This bonding can reduce volatilization of the silane coupling agent during melt mixing in the subsequent step (1-2).

In steps (1-1) and (1-1a), an organic peroxide may be present and a base resin may be present as long as the mixing is performed at a temperature below the decomposition temperature of the organic peroxide. may

Next, the mixture obtained in step (1-1a), the base resin (all or part), and the remaining components not mixed in step (1-1a) are combined in the presence of an organic peroxide. are melt-mixed at a temperature above the decomposition temperature of the organic peroxide.
The organic peroxide may be present when performing the step (1-1b), and may be mixed in the step (1-1a) or may be mixed in the step (1-1b). The amount of the organic peroxide compounded is not particularly limited, but is preferably 0.01 to 0.6 parts by mass, more preferably 0.05 to 0.3 parts by mass, relative to 100 parts by mass of the base resin.

In step (1-1b), the temperature for melt-mixing the above components is the decomposition temperature of the organic peroxide or higher, preferably the decomposition temperature of the organic peroxide + (25 to 110) ° C., for example, 150 to The temperature is 230°C. Other melt-mixing conditions, such as mixing time, can be appropriately set. As a result, the organic peroxide decomposes, acts on the silane coupling agent, and the grafting reaction of the silane coupling agent to the base resin proceeds.
The mixing method is not particularly limited as long as it is a method commonly used for rubbers, plastics and the like. The mixing device is appropriately selected according to, for example, the amount of the inorganic filler to be blended. A single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, or the like is used as a mixing device. A closed mixer such as a Banbury mixer or various kneaders is preferable in terms of dispersibility of the resin component and stability of the cross-linking reaction.

Thus, the step (1-1b) is carried out, and the base resin and the silane coupling agent are grafted. Thereby, a silane MB containing a silane graft resin is prepared.
In the above step (1-1a) using an inorganic filler, the silane coupling agent bonds or adsorbs with the chemically bonding site of the inorganic filler with its hydrolyzable silyl group. Further, the silane coupling agent undergoes a graft reaction with a graftable site of the base resin at its grafting reaction site during melt mixing in the step (1-1b). The mode of the grafting reaction includes a mode in which the silane coupling agent bonded or adsorbed to the inorganic filler through weak bonding desorbs from the inorganic filler and undergoes a grafting reaction to the base resin, and a silane cup bonded or adsorbed to the inorganic filler through strong bonding. Examples include a mode in which the ring agent undergoes a grafting reaction with the base resin while maintaining the bond with the inorganic filler.

Then, a silane crosslinkable resin composition is prepared by carrying out the above step (1-2).

In the method for preparing a silane crosslinkable resin composition, in the step (1), the step (1-1), particularly the step (1-1b), in the absence of a silanol condensation catalyst (for example, with respect to 100 parts by mass of the resin composition It is preferable to suppress the condensation reaction of the silane coupling agent by melt-mixing at a ratio of 0.01 parts by mass or less.

<Sheath Formation>
- Step of molding silane crosslinkable resin composition -
In the production method of the present invention, the step (2) of molding (arranging) the prepared silane crosslinkable resin composition on the outer peripheral surface of the conductor core is then carried out.
The step (2) may be any method as long as the conductor core can be coated with the silane crosslinkable resin composition, and an appropriate molding method is applied. Examples of molding methods include extrusion molding using an extruder, injection molding using an injection molding machine, and molding using other molding machines. In the present invention, extrusion molding in which the conductor core and the silane crosslinkable resin composition are co-extruded is preferred.
Extrusion can be performed using a general-purpose extruder. The extrusion molding temperature is appropriately set depending on various conditions such as the type of base resin or carrier resin and the extrusion speed (take-up speed), and is preferably set to 80 to 250°C, for example.
In the step (2), a powdery lubricant such as talc, a liquid lubricant such as silicone, and tape are applied to the outer peripheral surface of the conductor core to suppress the gap between the conductor core and the sheath. Adhesion can be appropriately controlled. The cross-sectional shape and thickness of the sheath can be adjusted using a mouthpiece of appropriate construction.
Step (2) is preferably carried out simultaneously with or consecutively with step (1-2). For example, a series of processes can be adopted in which the silane MB and the silanol condensation catalyst (or catalyst MB) are melt-mixed in a coating apparatus, and then extruded onto the outer peripheral surface of the conductor core.
Each MB can be mixed, for example dry-blended, in a non-melting state of the base resin or carrier resin prior to melt mixing in step (2) or step (1-1b). The dry blending method and conditions are not particularly limited, and examples thereof include dry blending in step (1-1a) and its conditions.
In step (2), in order to avoid a silanol condensation reaction, it is preferable that the silane MB and the silanol condensation catalyst are not kept in a mixed state at a high temperature for a long time.

- Step of cross-linking the silane cross-linkable resin composition -
In the production method of the present invention, step (3) is then carried out to crosslink the molded silane crosslinkable resin composition by contacting it with water. As a result, the hydrolyzable silyl groups of the silane coupling agent are hydrolyzed into silanol (OH groups bonded to silicon atoms), and the silanol condensation catalyst present in the silane crosslinkable resin composition causes the hydroxyl groups of the silanol to condense.

Step (3) can be performed by a normal method. The condensation reaction proceeds at room temperature in the presence of a silanol condensation catalyst. Therefore, it is not necessary to actively bring the silane crosslinkable resin composition disposed on the outer peripheral surface of the conductor core into contact with water. In order to promote this cross-linking reaction, the silane cross-linkable resin composition can also be brought into contact with moisture.

In this process, the silane coupling agent, which is strongly bonded to the inorganic filler, is resistant to silanol condensation reaction, maintains the bond with the inorganic filler, and enables strong adhesion (high affinity) between the base resin and the inorganic filler. do. On the other hand, the silane coupling agent weakly bonded to the inorganic filler undergoes a silanol condensation reaction to crosslink the base resins with each other via silanol bonds (siloxane bonds).

Thus, the production method of the present invention is carried out, and a sheath made of the silane crosslinked product (silanol condensation hardened product) of the silane crosslinkable resin composition is formed on the outer peripheral surface of the conductor core.
The silane crosslinked product is a silane graft resin obtained by grafting a specific amount of a silane coupling agent to a base resin containing ethylene rubber or a styrene elastomer, and the hydrolyzable silyl of the silane coupling agent bonded to the silane graft resin. The groups are crosslinked by silanol condensation. This silane graft resin contains a crosslinked resin in which base resins are bonded to each other via a silane coupling agent (siloxane bond).
The silanol condensation cured product of the silane crosslinkable resin composition containing an inorganic filler is at least two crosslinked resins depending on the bonding strength between the inorganic filler and the silane coupling agent in the above step (1-1a), that is, In addition to the above crosslinked resin, the base resin contains a crosslinked resin bonded (crosslinked) to the inorganic filler via a silane coupling agent.
The silane crosslinked product has, as constituent components, a constituent component derived from at least one of ethylene rubber and a styrene elastomer, a constituent component derived from a silane coupling agent, and preferably a constituent component derived from an inorganic filler.

For each step in the above production method, furthermore, the reaction in the silane crosslinking method and the form of the condensed cured product obtained, for example, the description of JP-A-2017-145370 can be applied as appropriate, and the content described in this publication can be applied as it is. Incorporated as part of the description herein.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention is not limited to these.
In Table 1, the numerical values relating to the blending amounts in each example represent parts by mass unless otherwise specified. In each component column, "-" means that the amount of the corresponding component is 0 parts by mass.

Details of each component (compound) shown in Table 1 are shown below.
<Base resin>
- Ethylene rubber -
Mitsui 3092M: trade name, ethylene-propylene-diene rubber, manufactured by Mitsui Chemicals - styrene elastomer -
Septon 4077: trade name, SEPS, manufactured by Kuraray - polyolefin resin -
Evolue SP1540: trade name, LLDPE, manufactured by Prime Polymer)
- Organic mineral oil -
Diana Process PW-90: trade name, paraffin oil, manufactured by Idemitsu Kosan <Inorganic filler>
Magsis LN-6: trade name, magnesium hydroxide, manufactured by Kojima Chemical Co., Ltd. <Silane coupling agent>
KBM-1003: trade name, vinyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. <organic peroxide>
Perhexa 25B: trade name, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, decomposition temperature 179° C., manufactured by NOF CORPORATION <silanol condensation catalyst>
ADEKA STAB OT-1: trade name, dioctyltin dilaurate, manufactured by ADEKA

<Production of conductor core>
First, two crosslinked polyethylene wires (thin wire: conductor outer diameter 1.4 mm, resin layer thickness 0.3 mm) with a conductor cross-sectional area of 0.25 SQ are twisted in pairs, and the thin wire stranded wire (twisted 1%) was obtained. The obtained stranded wire of the thin wire and two crosslinked polyethylene wires having a conductor cross-sectional area of 1.8 SQ (large diameter wire: conductor outer diameter 2.6 mm, resin layer thickness 0.3 mm) are twisted together. , the conductor core shown in FIG.

In Examples 1 to 12, 95% by mass of the total 100% by mass shown in each example column in Table 1 was used as the base resin for preparing the silane MB, and the remaining 5% by mass was used for preparing the catalyst MB.

<Example 1>
A four-core composite cable shown in FIG. 1 was manufactured as follows.
(Preparation of silane MB)
The silane coupling agent and the organic peroxide were mixed (dry blended) at 25° C. in the amounts shown in Example 1 column of Table 1, and then the inorganic filler was added thereto and mixed at 30° C. (dry blended). (Step (1-1a)). Next, the obtained mixture and the base resin in the compounding amounts shown in Example 1 column of Table 1 (excluding the remainder used as the carrier resin) are put into a Banbury mixer and melt-mixed at 120 to 200° C. for 10 minutes. After that, the material was discharged at a discharge temperature of 200° C. and passed through a feeder ruder to obtain silane MB pellets (step (1-1b)).
By melt-mixing in the Banbury mixer, a silane graft reaction was caused to synthesize a silane graft resin.

(Preparation of catalyst MB)
After charging the carrier resin (the balance of the compounding amount shown in Table 1, Example 1 column) and the silanol condensation catalyst in the compounding amount shown in Table 1, Example 1 column into a Banbury mixer and melt-mixing at 170 ° C. , the material was discharged at a temperature of 180° C. and passed through a feeder ruder to obtain catalyst MB pellets.

(extrusion coating)
Next, the prepared silane MB pellets and catalyst MB pellets were dry-blended at the compounding ratio shown in the Example 1 column of Table 1. The resulting dry blend was introduced into an extruder equipped with a screw having a diameter of 90 mm (ratio of screw effective length L to diameter D: L/D = 24, compression section screw temperature 190°C, head temperature 200°C). did. While melt-mixing the dry blend (preparing the silane crosslinkable resin composition) in the extruder, it is directly extruded (placed) on the outer peripheral surface of the twisted conductor core with a thickness of 1 mm to form a coating with an outer diameter of 8 mm. A conductor was obtained (step (1-2) and step (2)).

(Silanol condensation reaction)
The coated conductor thus obtained was left in an atmosphere of 60° C. and 95% relative humidity for 24 hours to contact with water (step (3)).

In this way, a composite cable (outer diameter 8 mm) of Example 1 having a sheath with a layer thickness of 1 mm formed from the silanol condensation cured product of the silane crosslinkable resin composition was produced.

<Examples 2 to 12>
Composite cables of Examples 2 to 12 were produced in the same manner as in Example 1, except that a silane crosslinkable resin composition having the composition shown in Table 1 was prepared.

<Comparative Example 1>
A sheath was formed by a chemical cross-linking method in the following manner, and a four-core composite cable shown in FIG. 1 was manufactured.
As shown in the column of Comparative Example 1 in Table 1, each component was put into a Banbury mixer and melt-mixed at 180°C for 10 minutes, then the resulting mixture and an organic peroxide were mixed and blended at 100°C for 3 minutes. and passed through a feeder ruder to obtain pellets of the resin composition. As the organic peroxide, Perkadox BCFF (trade name, manufactured by Kayaku Akzo Co., Ltd.) was used in an amount of 0.5 parts by mass based on 100 parts by mass of the base resin.
Then, pellets of the prepared resin composition were extruded into an extruder equipped with a screw having a diameter of 90 mm (ratio of screw effective length L to diameter D: L/D = 24, compression part screw temperature 190 ° C., head temperature 200 ° C. ). In this extruder, pellets of the resin composition were melt-mixed and directly extruded (arranged) with a thickness of 1 mm on the outer peripheral surface of the twisted conductor core to obtain a coated conductor with an outer diameter of 8 mm.
Next, using a crosslinking tube, the coated conductor (resin composition) was chemically crosslinked under the conditions of 200° C., steam pressure of 1.5 MPa, and reaction time of 5 minutes.
Thus, a composite cable (outer diameter 8 mm) of Comparative Example 1 having a sheath with a layer thickness of 1 mm formed by a chemical cross-linking method was produced.

<Comparative Example 2>
A sheath was formed by an electron beam cross-linking method in the following manner, and a four-core composite cable shown in FIG. 1 was manufactured.
As shown in the column of Comparative Example 2 in Table 1, each component was put into a Banbury mixer and melt-mixed at 120 to 200 ° C. for 10 minutes, then discharged at a material discharge temperature of 200 ° C., and passed through a feeder ruder to produce a resin composition. A pellet was obtained.
A sheath was formed as follows using the prepared conductor core and the obtained pellet. That is, the obtained pellets were introduced into an extruder equipped with a screw having a diameter of 90 mm (ratio of screw effective length L to diameter D: L/D = 24, compression section screw temperature 190 ° C., head temperature 200 ° C.). did. While the pellets were melted in this extruder, they were directly extruded (arranged) on the outer peripheral surface of the conductor core with a wall thickness of 1 mm to obtain a cable with an outer diameter of 8 mm.
Next, the resin composition placed on the outer peripheral surface of the conductor core was irradiated with an electron beam at an acceleration voltage of 500 kV.
In this way, a composite cable (outer diameter 8 mm) of Comparative Example 2 having a sheath with a layer thickness of 1 mm formed from the electron beam cross-linked product was produced.

<Comparative Example 3>
A four-core composite cable shown in FIG. 1 was manufactured by forming a sheath from a non-crosslinked resin composition in the following manner.
Comparative Example 3 having a sheath with a layer thickness of 1 mm formed of a non-crosslinked resin composition in the same manner as in Comparative Example 2, except that the resin composition disposed on the outer peripheral surface of the conductor core was not irradiated with an electron beam. A composite cable (8 mm outer diameter) was produced.

The composite cables of the manufactured examples and comparative examples are 4-core composite cables in which a large-diameter electric wire is an EPB cable (power line) and a small-diameter electric wire is an ABS cable (signal line).

The manufactured composite cables were evaluated as follows, and the results are shown in Table 1.
<Heat resistance test>
The amount of change in outer diameter was measured as the amount of heat deformation according to the heat deformation test specified in UL758. Specifically, using the manufactured composite cable, a heat resistance test was performed under the conditions of a temperature of 121 ° C. and a load of 0.4 kgf, and the amount of change in outer diameter before and after the test was calculated from the sheath thickness. The value was defined as the amount of heat deformation. The sheath thickness was calculated from the cable outer diameter and the twisted diameter of the conductor core.
The heat resistance of each cable was evaluated according to the following criteria based on the amount of heat deformation (%) measured. The pass of this test is "△" and "○".
“○”: Less than 30% “△”: 30% or more and less than 50% “×”: 50% or more

<Terminal workability>
At 100 mm of the end of the cable, peelability was evaluated when the sheath was stripped off.
Specifically, a cut was made in the circumferential direction perpendicular to the axial direction of the composite cable to a depth of 90% of the coating thickness of the composite cable. Next, the sheath of one of the composite cables was grasped at this cut, and the other composite cable was pulled out.
With respect to the composite cable pulled out in this way, the terminal workability test of the sheath was evaluated according to the following criteria. The pass of this reference test is "△".
“〇”: When the pulled out cable has no sheath remaining to be pulled out and the extension of the sheath end of the pulled out cable is less than 1.0 mm “△”: The pulled out cable has the remaining sheath to be pulled out When the sheath end of the pulled out cable is stretched 1.0 mm or more and 5 mm or less "X": When the sheath to be pulled out remains in the pulled out cable

<Fogging resistance>
It was tested according to the method specified in ISO6452.
Specifically, a test piece (approximately 31 g) was taken from the sheath of each cable, and tested at a test temperature of 120° C. and a test time of 24 hours. The temperature of the cold plate was kept constant at 21°C. Judgment was made by measuring the change in haze value of the cooling plate.
Evaluation was made according to the following criteria. The pass of this examination is "○".
“〇”: less than 10% “△”: 10% or more and less than 20% “×”: 20% or more

<Reference test: flex resistance test>
FIG. 2 is a schematic view of the apparatus used in this test, viewed from the axial direction of the mandrel.
As shown in FIG. 2, the cable 102 is vertically passed between two mandrels 51 and 52 arranged horizontally and parallel to each other and between the pressers 61 and 62 for preventing shaking, and a weight is placed below the cable 102. 7 was installed. In this state, the upper end of the cable 102 was bent so as to alternately come into contact with the upper outer peripheries of the left and right mandrels 51 or 52 (repeatedly left and right alternately). The number of times of bending was counted as one time when the cable 102 was bent so as to be in contact with the outer circumference of either the left or right mandrel 51 or 52 . The test conditions were a mandrel diameter of 10 mm, a left-right bending angle of 90°, and a bending rate of 60 bends/minute. The length to be bent was prepared so as to be in contact with , and the test was performed in an atmosphere of 25°C. The cable was connected in series in a loop and energized, and the number of flexing times until breakage occurred was measured.
The evaluation was performed according to which of the following criteria the number of times of bending until the insulated wire first broke was included, and the passing of this test was "Δ" and "○".
○: 100,000 times or more △: 70,000 times or more and less than 100,000 times ×: Less than 50,000 times

As shown in Table 1, when the outer surface of the core is provided with a sheath formed by a silane cross-linking method using the silane cross-linkable resin composition defined in the present invention, the composite cable has heat resistance, anti-fogging and It can be seen that the terminal processability is also at a high level.
The composite cable of Comparative Example 1, in which a sheath formed by cross-linking a cross-linkable resin composition by a chemical cross-linking method is provided on the outer surface of the core, is inferior in terminal workability and bending resistance. That is, it was difficult to peel the sheath from the core (resin layer), and bending stress of the sheath was likely to be transmitted directly to the insulated wire, causing rapid disconnection of the conductor. This is believed to be due to the fact that the resin layer and the sheath of the insulated wire are strongly adhered by cross-linking the cross-linkable resin composition molded on the outer surface of the core together with the core through (passing through) the cross-linking pipe. .
In addition, the composite cable of Comparative Example 2, in which the outer surface of the core is provided with a sheath formed by cross-linking the cross-linkable resin composition by electron beam cross-linking, is inferior in fogging resistance. This is presumably because the low-molecular-weight component produced as a by-product during the cross-linking volatilized from the sheath.
Furthermore, the composite cable of Comparative Example 3, which has a sheath formed of an uncrosslinked resin composition on the outer surface of the core, is inferior in heat resistance.

On the other hand, the composite cable of the example having the sheath formed of the silanol condensation cured product of the silane crosslinkable resin composition on the outer surface of the core has heat resistance and fogging resistance, and furthermore, the sheath and core Terminal workability can be improved to an excellent level even if a separator is not interposed therebetween. This is because silane cross-linking can be carried out under relatively mild conditions when forming the sheath, so that by-products of low molecular weight components (volatile substances) that cause clouding or contamination can be suppressed. It is thought that it is possible to prevent excessive adhesion with.
In particular, when the base resin contains at least one of ethylene rubber and styrene-based elastomer, even with a large-diameter cable having an outer diameter of 8 mm, it is possible to prevent excessive adhesion between the resin layer and the sheath, thereby improving bending resistance. can be done.

REFERENCE SIGNS LIST 1 composite cable 2 large-diameter wire 21 conductor 22 resin layer 3 small-diameter wire 31 conductor 32 resin layer 4 sheath 51, 52 mandrel 61, 62 presser for preventing shaking 7 weight 102 cable

In Examples 1 to 11 and Reference Example 12, 95% by mass of the total 100% by mass shown in each Example column and Reference Example column in Table 1 was used as the base resin for preparing silane MB, and the remaining 5% by mass was used. Used for preparation of catalyst MB.

<Examples 2 to 11 and Reference Example 12>
Composite cables of Examples 2 to 11 and Reference Example 12 were produced in the same manner as in Example 1, except that the silane crosslinkable resin composition having the composition shown in Table 1 was prepared.

The composite cables of the manufactured examples , reference examples, and comparative examples are four-core composite cables in which the large-diameter electric wire is an EPB cable (power line) and the small-diameter electric wire is an ABS cable (signal line).

On the other hand, the composite cables of Examples and Reference Examples , which have a sheath formed of a silanol condensation cured product of a silane crosslinkable resin composition on the outer surface of the core, have heat resistance and fogging resistance, and furthermore, the sheath and Terminal workability can be improved to an excellent level even if a separator is not interposed between the core and the core. This is because silane cross-linking can be carried out under relatively mild conditions when forming the sheath, so that by-products of low molecular weight components (volatile substances) that cause clouding or contamination can be suppressed. It is thought that it is possible to prevent excessive adhesion with.
In particular, when the base resin contains at least one of ethylene rubber and styrene-based elastomer, even with a large-diameter cable having an outer diameter of 8 mm, it is possible to prevent excessive adhesion between the resin layer and the sheath, thereby improving bending resistance. can be done.

Claims (12)

A method for manufacturing a composite cable having a sheath surrounding the outer surface of a core comprising at least a plurality of large-diameter wires having a resin layer on the outer periphery of the conductor and a plurality of small-diameter wires having a resin layer on the outer periphery of the conductor. There is
molding a silane crosslinkable resin composition containing a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst on the outer surface of the core;
contacting the molded silane crosslinkable resin composition with water;
A method of manufacturing a composite cable having 2. The method of manufacturing a composite cable according to claim 1, wherein the base resin contains at least one of ethylene rubber and styrene elastomer. 3. The method for manufacturing a composite cable according to claim 1, wherein the silane crosslinkable resin composition contains 1 to 15 parts by mass of the silane coupling agent with respect to 100 parts by mass of the base resin. The method for manufacturing a composite cable according to any one of claims 1 to 3, wherein the base resin contains an organic mineral oil. The method for producing a composite cable according to any one of claims 1 to 4, wherein the silane crosslinkable resin composition contains 10 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the base resin. A composite cable comprising a sheath surrounding the outer surface of a core composed of at least a plurality of large-diameter wires having a resin layer on the outer periphery of the conductor and a plurality of small-diameter wires having a resin layer on the outer periphery of the conductor,
A composite cable in which the sheath is made of a silanol condensation cured product of the silane crosslinkable resin composition described below.
<Silane crosslinkable resin composition>
A silane crosslinkable resin composition containing a base resin, a silane coupling agent grafted to the base resin, and a silanol condensation catalyst 7. The composite cable according to claim 6, wherein said base resin contains at least one of ethylene rubber and styrenic elastomer. 8. The composite cable according to claim 6, wherein the silane crosslinkable resin composition contains 1 to 15 parts by mass of the silane coupling agent with respect to 100 parts by mass of the base resin. A composite cable according to any one of claims 6 to 8, wherein the base resin contains an organic mineral oil. The composite cable according to any one of claims 6 to 9, wherein the silane crosslinkable resin composition contains 10 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the base resin. The composite cable according to any one of claims 6 to 10, wherein the composite cable is for vehicle brake control. Two of the plurality of large-diameter wires serve as a pair of power wires that supply power from the control device of the electric parking brake to the actuator,
Two of the plurality of thin wires are used as a pair of signal wires for transmitting signals from the antilock braking system sensor to the antilock braking system control device.
The composite cable of Claim 11.

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